Air conditioner control

ABSTRACT

A thermostatic air conditioner control for use with individual unit air conditioners having a thermostatic switch disposed at a location remote from the air conditioner. The control includes circuitry interposed between the air conditioner and a source of electrical energy operative a selected time interval after closure of said thermostatic switch to energize a socket in which the air conditioner is plugged, and operative a selected time interval after opening of said thermostatic switch to de-energize the socket.

United States Patent [191' Valenzuela, Jr.

[ Jan. 15, 1974 p AIR CONDITIONER CONTROL [76] Inventor: EphrenValenzuela, Jr., 1119 2nd Ave., Chula Vista, Calif. 9201 1 [22] Filed:Mar. 15, 1972 21 Appl. No.1 234,825

52 us. C1 62/158, 62/261,62/262, 62/231 51 Int. Cl. ..G05d 23/32 [58]Field OfSearch 62/157,158, 261,

[56] References Cited UNITED STATES PATENTS 3,054,271 9/1962 McGrath62/158 3,101,432 8/1963 3,142,013 7/1964 3,128,607 4/1964 6/1971Cheseboro 62/158 10/1972 Barry 62/158 Primary Examiner william .1. WyeAzt0rney-Ma)t Dressler et a1.

[57] ABSTRACT A thermostatic air conditioner control for use withindividual unit air conditioners having a thermostatic switch disposedat a location remote from the air conditioner. The control includescircuitry interposed between the air conditioner and a source ofelectrical energy operative a selected time interval after closure ofsaid thermostatic switch to energize a socket in which the airconditioner is plugged, and operative a selected time interval afteropening of said thermostatic switch to de-energize the socket.

9 Claims, 2 Drawing Figures AIR CONDITIONER CONTROL BACKGROUND Manyindividual unit air conditioners such as room air conditioners do nothave temperature responsive controls for monitoring the operationthereof. Those air conditioners which do have controls are often locatedin positions within the room which makes it inconvenient to operate suchcontrols or which renders such controls inaccessible.

Even when such air conditioners have the desired controls and when thosecontrols are accessible, the controls of such air conditioners areresponsive to the temperature adjacent to the air conditioner ratherthan the temperature at desired locations in the room in which the airconditioner is disposed.

One of the problems in the use'of room or individual unit airconditioners is to control the operations of such units to providedesired temperatures at desired locations in the room or area beingcooled.

Another problem in the operation of room air conditioners is thetendency to turn the air conditioner on immediately after being turnedoff. This type of manipulation should be avoided in order to insureproper operation of the air conditioner compressor.

In most circumstances, an overload relay is installed in the compressorcircuit, the compressor being a pump having high gas pressures. When thecompressor is started properly, gas pressures are equal on both sides ofthe compressor. Once the compressor is started, gas pressures on oneside are substantially greater than on the other side. To start acompressor under proper circumstances requires a large surge of current.Once at operating conditions, the normal current draw is experienced.

When an air conditioner is turned on and off rapidly, the compressor isnot starting with equal gas pressures, but rather it is pumping againsthigher than normal pressures. When this occurs, excessive current drawis experiencedduring starting and the overload relay protecting thecompressor is operative to prevent damage to the air conditioner or tothe electrical circuitry to which the air conditioner is connected. Thisoverload cycling can be prevented by waiting for a few minutes betweencompressor starts to allow gas pressure to equalize.

Unfortunately, most people do not understand this operational limitationand do not follow this simple precaution. As a result, it often occursthat the breaker or fuse in the circuit to which the air conditioner isconnected blows since higher fuse ratings that would accommodate theseexcess current surges are not permitted in ordinary wiring circuits.

Therefore, it would also be desirable not only to operate an airconditioner in response to temperature levels at locations remote fromthe installation thereof but to insure that overload problems whichresult from improper starting of the air conditioner compressor areavoided.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the presentinvention there is provided an air conditioner control which isoperative in response to selected temperatures in a room in which an airconditioner is installed at locations remote from the air conditioner,and which concurrently provides the desired protection to prevent theair conditioner from being improperly started.

In accordance with the present invention, a self contained controlcircuit is electrically interposed between the air conditioner and thesource of electrical energy and includes a remotely situatedthermostatic switch disposed at the location where it is desired toobtain selected temperature levels.

The control circuit of the present invention is simple, compact andprovides the desired control and safety functions while being adaptedfor use with any standard individual air conditioning units such as awindow room air conditioners.

In accordance with the present invention, the air conditioner is pluggedinto the control unit which is plugged into the normal wall outlet. Thecontrol unit includes electrical circuitry interposed between the socketinto which the air conditioner is plugged and the wall outlet forselectively controlling energization of the socket and, thereby, the airconditioner. This control circuitry is a low voltage circuitry whichprovides full potential to the socket into which the air conditioner isplugged.

Incorporated as part of the control is a remotely located thermostatwhich is affixed at a location at which it is desired to monitor theambient room temperature. The thermostat, as is well known, operates toclose a thermostatic switch when the temperature in the room at thethermostat location increases to a selected level.

Upon closure of the thermostatic switch, a time delay relay connected inseries therewith and across the secondary of a step down transformer isenergized. A time delay control switch is connected in series with acontrol relay across the secondary of the step down transformer. Thetime delay relay is operative at a selected time interval after closureof the thermostatic switch to close its associated contacts and energizecontrol relay. The control relay closes its normally open contactsconnected in series with the socket to connect the socket to the walloutlet and energize the socket whereby the air conditioner plugged intothe socket is operated.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and of one embodiment thereof, from the claims and from theaccompanying drawings in which each and every detail shown is fully andcompletely disclosed as a part of this specification in which likenumerals refer to like parts.

I BRIEF DESCRIPTION OF THE DRAWING FIG. I is a diagramatic view showingan air conditioner connected to the control circuit of the presentinvention and one location of the remotely located thermostat:

FIG. 2 is a schematic electrical diagram of the control circuit of thepresent invention.

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail one specific embodimennwith the understanding that the presentdisclosure is to be considered as an exemplification of the principlesof the invention and is not intended to limit the invention to theembodiment illustrated.

In FIG. 1 there is shown a room air conditioner 10 disposed, as is wellknown, in window 12. The room air conditioner 10 is provided with a cord14, on the end of which is disposed a plug 16 adapted for insertion intoan electrical wall outlet 18. The air conditioner plug 16, as seen inFIG. 1, is inserted into the self contained control 20 of the presentinvention which in turn is plugged into the wall outlet 18. A thermostat22, fonning part of the control of the present invention, is disposed ata location remote therefrom, such as at 24 as shown in FIG. 1 adjacentto a bed disposed in the room 28 at a location remote from the airconditioner itself. The thermostat is connected to the self containedcontrol by an appropriate card 30.

FIG. 2 shows shows schematically the electrical circuit incorporated aspart of the present invention. Within the control unit 20 there is anappropriate plug 32 adapted for insertion into the wall outlet 18. Theplug 32 is connected across the primary 34 of a step down transformer36, the secondary 38 of which provides a voltage of about 24 volts.

The thermostat 22 incorporates a thermostatic switch 40 responsive tothe ambient temperature at the thermostat location 24. The switch 40closes when the ambient temperature sensed by the thermostat 22 reachesa selected level selectable by the thermostat, and opens when theambient temperature falls below the selected temperature.

The thermostatic switch 40 is connected in series with a time delayrelay 42, this series combination being connected across the secondary38 of a step down transformer 36. A control relay coil 44 and thenormally open contacts 46 of the time delay relay 42 are connected inseries with each other and are also connected across the secondary 38 ofthe step down transformer 36. The normally open contacts 48 of thecontrol relay 44 are connected in series with the socket 50 which seriescombination is connected across the primary 34 of the step downtransformer 36, i.e., to the wall outlet 18.

In operation, when the temperature in the room 28 rises to the valueselected on the thermostat 22, the thermostatic switch 40 closes tocomplete the circuit across the secondary 38 of the step downtransformer 36 through the time delay relay 42. The energized time delayrelay 42 is operative after a selected time interval, which may be fromseveral seconds to several minutes, to close its associated normallyopen contacts 46 connected in series with the control relay coil 44across the secondary of the step down transformer.

When the control relay coil 44 is thus energized, it closes its normallyopen contacts 48 connected in series with the socket 50 therebyconnecting the socket across the primary 34 of the step down transformer36 to energize the socket and the air conditioner 10 plugged into thesocket 50.

It can be appreciated that the time delay relay utilized in the controlof the present invention can be selected to operate at any desired delayinterval, the interval selected typically being governed by the minimumwaiting period required for turning the air conditioner on after it hasonce turned off. Thus, not only does the present invention automaticallycontrol the operation of the air conditioner as a function of sensedambient room temperature, but provides the necessary protection againstimproper operation of the air conditioner by precluding improperrestarts of the compressor.

In one illustrative embodiment the thermostat utilized was an lTTGeneral Controls room thermostat,

4 Catalogue No. T99JV300J, Model H; the time delay relay utilized was aGeneral Electric MARS relay No. 276; the control relay was an RBM relay,Catalogue No. -230; and the step down transformer was a Honeywelltransformer No. AT870A-1106.

It can be appreciated that the above identified components are merelyexemplary of components which might be utilized and other suitablecomponents may be substituted.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the true spirit andscope of the novel concept of the invention. It is, of course, intendedto cover by the appended claims all such modifications as fall withinthe scope of the claims.

What is claimed is:

1. A thermostatic air conditioner control adapted for use withindividual unit air conditioners comprising in combination:

means for connecting said control to a source of electrical energy;

socket means adapted to receive the leads of said air conditioner unit;

switching circuit means adapted to selectively interconnect said sourceconnecting means and said socket means to energize said socket meansand, thereby, said air conditioner unit;

said switching circuit means including first temperature sensitiveswitching means responsive to surrounding ambient temperatures andactuated in response to a selected ambient temperature; timing meansenergized in response to the operation of said temperature sensitiveswitching means and operative a selected time interval afterenergization thereof;

relay means connected to be energized in response to operation of saidtiming means;

relay switch means operative in response to energization of said relaymeans for interconnecting said source connecting means and said socketmeans to energize said socket means.

2. A control as claimed in claim 1 wherein said source connecting meansis a plug adapted to be inserted into an AC. wall outlet connected to asource of AC. voltage.

3. A control as claimed in claim 2 wherein said plug is connected to theprimary of a step down transformer, and wherein said socket and saidrelay switch means are connected in series with each other across theprimary of said step down transformer.

4. A control as claimed in claim 3 wherein said temperature responsiveswitching means and said timing means are connected in series with eachother and across the secondary of said step down transformer.

5. A control as claimed in claim 4 including control switch meansconnected in series with said relay means across the secondary of saidstep down transformer, said control switch means closing in response tooperation of said timing means to energize said relay means.

6. A control as claimed in claim 5 wherein said temperature sensitiveswitching means is located remotely from the remainder of said control,whereby said control is adapted to be operative in response to selectedambient temperature at a location remote therefrom and remote from theair conditioner unit connected to said socket means.

7. A control as claimed in claim 6 wherein said temperature responsiveswitching means is a thermostat and includes means for selecting theambient temperature at which said temperature responsive switching meanscloses.

8. A control as claimed in claim 7 wherein said timing means includes atime delay relay connected in series with said temperature responsiveswitching means, said time delay relay being operative a selectable timeinterval after closure of said temperature responsive switching means toclose said control switch means, and being operative a selected timeinterval after opening of said temperature sensitive switch means toopen the contacts of said control switch means.

9. A thermostatic air conditioner control for controlling the operationof a room air conditioner in response to variations in the temperatureof the room at a point remote from said air conditioner comprising incombination:

a thermostatic switch disposed at a location remote from said airconditioner for sensing ambient temperatures at said location, saidthermostatic switch including means for selecting a desired temperatureand switching means closing in response to said sensed ambienttemperature being above said selected temperature and opening inresponse to said sensed ambient temperature being below said selectedtemperature;

delay relay operative a selected time interval after closing of saidthermostatic switch to close said time delay contacts and energize saidrelay coil; normally open relay contacts closing in response to theenergization of said relay coil, said relay contacts being connected inseries with a socket across the primary of said step down transformer;whereby said socket is connected to said source of electrical energy aselected time interval after closure of said thermostatic switch and isdisconnected from said source of electrical energy a selected timeinterval after opening of said thermostatic switch to energize anddeenergize a room air conditioner connected to said socket.

1. A thermostatic air conditioner control adapted for use withindividual unit air conditioners comprising in combination: means forconnecting said control to a source of electrical energy; socket meansadapted to rEceive the leads of said air conditioner unit; switchingcircuit means adapted to selectively interconnect said source connectingmeans and said socket means to energize said socket means and, thereby,said air conditioner unit; said switching circuit means including firsttemperature sensitive switching means responsive to surrounding ambienttemperatures and actuated in response to a selected ambient temperature;timing means energized in response to the operation of said temperaturesensitive switching means and operative a selected time interval afterenergization thereof; relay means connected to be energized in responseto operation of said timing means; relay switch means operative inresponse to energization of said relay means for interconnecting saidsource connecting means and said socket means to energize said socketmeans.
 2. A control as claimed in claim 1 wherein said source connectingmeans is a plug adapted to be inserted into an A.C. wall outletconnected to a source of A.C. voltage.
 3. A control as claimed in claim2 wherein said plug is connected to the primary of a step downtransformer, and wherein said socket and said relay switch means areconnected in series with each other across the primary of said step downtransformer.
 4. A control as claimed in claim 3 wherein said temperatureresponsive switching means and said timing means are connected in serieswith each other and across the secondary of said step down transformer.5. A control as claimed in claim 4 including control switch meansconnected in series with said relay means across the secondary of saidstep down transformer, said control switch means closing in response tooperation of said timing means to energize said relay means.
 6. Acontrol as claimed in claim 5 wherein said temperature sensitiveswitching means is located remotely from the remainder of said control,whereby said control is adapted to be operative in response to selectedambient temperature at a location remote therefrom and remote from theair conditioner unit connected to said socket means.
 7. A control asclaimed in claim 6 wherein said temperature responsive switching meansis a thermostat and includes means for selecting the ambient temperatureat which said temperature responsive switching means closes.
 8. Acontrol as claimed in claim 7 wherein said timing means includes a timedelay relay connected in series with said temperature responsiveswitching means, said time delay relay being operative a selectable timeinterval after closure of said temperature responsive switching means toclose said control switch means, and being operative a selected timeinterval after opening of said temperature sensitive switch means toopen the contacts of said control switch means.
 9. A thermostatic airconditioner control for controlling the operation of a room airconditioner in response to variations in the temperature of the room ata point remote from said air conditioner comprising in combination: athermostatic switch disposed at a location remote from said airconditioner for sensing ambient temperatures at said location, saidthermostatic switch including means for selecting a desired temperatureand switching means closing in response to said sensed ambienttemperature being above said selected temperature and opening inresponse to said sensed ambient temperature being below said selectedtemperature; circuit means electrically connecting said switching meansin series with a time delay relay, said series combination of saidswitching means and said time delay relay being connected across thesecondary of a step down transformer; means connecting the primary ofsaid step down transformer to a source of electrical energy; a relaycoil, and time delay switch contacts operatively associated with saidtime delay relay, said time delay relay contacts and said relay coilbeing connected in series with each other across said secondary of saidstep down transformer, sAid time delay relay operative a selected timeinterval after closing of said thermostatic switch to close said timedelay contacts and energize said relay coil; normally open relaycontacts closing in response to the energization of said relay coil,said relay contacts being connected in series with a socket across theprimary of said step down transformer; whereby said socket is connectedto said source of electrical energy a selected time interval afterclosure of said thermostatic switch and is disconnected from said sourceof electrical energy a selected time interval after opening of saidthermostatic switch to energize and deenergize a room air conditionerconnected to said socket.